Objective:The aim of our study was to investigate the expression of guanine nucleotide exchange factor Dock180 in ovarian tumor,and its significance in the initiation and progression of ovarian cancer.Methods:Immunohistochemical staining with SP method was conducted to identify the expression of Dock180 protein in epithelial ovarian tumor in 68 cases.Results:Dock180 present with higher expression in ovarian cancer,as compared with than that in low malignant tumor and benign ovarian tumor (P < 0.01).In ovarian cancer,Dock180 expression was increased with the increased FIGO stage and grade.Conclusion:Dock180 overexpression may play an important role in the development and progression of ovarian cancer and it could be used as a new measurement of malignant biological behavior of ovarian cancer. Objective: The aim of our study was to investigate the expression of guanine nucleotide exchange factor Dock180 in ovarian tumor, and its significance in the initiation and progression of ovarian cancer. Methods: Immunohistochemical staining with SP method was conducted to identify the expression of Dock 180 protein in epithelial ovarian tumor in 68 cases. Results: Dock 180 present with higher expression in ovarian cancer, as compared with than that in low malignant tumor and benign ovarian tumor (P <0.01). In ovarian cancer, Dock 180 expression was increased with the increased FIGO stage and grade. Conflusion: Dock 180 overexpression may play an important role in the development and progression of ovarian cancer and it could be used as a new measurement of malignant biological behavior of ovarian cancer.